The present invention is directed to methods and devices for occluding a patient""s ascending aorta and maintaining circulation of oxygenated blood in the patient when the patient""s heart is arrested. Such devices and methods are useful for performing various procedures on a patient""s vascular system and heart such as the procedures described in U.S. Pat. Nos. 5,584,803 and 5,682,906 which describe coronary artery bypass grafting (CABG) and valve procedures, respectively. Another device and method for occluding a patient""s ascending aorta is described in Reissue U.S. Pat. No. 35,352.
The methods and devices described in the above-mentioned patents use an internal occlusion device to occlude the ascending aorta rather than a conventional external cross-clamp. Use of an internal occlusion device may reduce strokes as compared to conventional external cross-clamps since external cross-clamps distort and compress the aorta which may release emboli leading to strokes.
It is an object of the invention to provide alternative methods and devices for occluding a patient""s ascending aorta and maintaining circulation of oxygenated blood when the patient""s heart is arrested.
In accordance with the object of the invention, the present invention provides alternative methods and devices for occluding a patient""s ascending aorta and maintaining circulation of oxygenated blood in a patient when the patient""s heart is arrested.
In a first preferred method and device of the present invention, an aortic occlusion device having a blood delivery lumen and an occluding member is introduced into the patient""s aortic arch. The occluding member has an interior in fluid communication with the blood delivery lumen so that delivery of oxygenated blood inflates the occluding member. An advantage of this method is that a separate inflation lumen is not necessary. The aortic occlusion device preferably passes through a cannula having a y-arm with the aortic occlusion catheter passing through an arm of the y-arm. The other arm of the y-arm connector is coupled to the source of oxygenated blood so that bypass support can be maintained even when the aortic occlusion device has been removed.
In another preferred method and device, oxygenated blood is delivered to the patient through the aortic occlusion catheter. The aortic occlusion catheter also passes through a cannula with a y-arm connector so that bypass support can be maintained when the aortic occlusion device is removed. The aortic occlusion device also preferably includes a lumen for delivering cardioplegic fluid and venting the ascending aorta and a pressure lumen for measuring pressure in the ascending aorta. If the lumens are not provided in the aortic occlusion device, delivery of cardioplegic fluid, venting of the ascending aorta and pressure monitoring may be accomplished with the cannula.
In another preferred device, the aortic occlusion device has an occluding member mounted to a side of the catheter. The occluding member has a pathway therethrough which is in communication with a lumen in the aortic occlusion catheter. The pathway directs cardioplegic fluid toward the coronary ostia while the aortic occlusion device directs the oxygenated blood in the direction of normal blood flow in the aorta.
According to another aspect of the invention, a device for occluding a patient""s aorta comprises a cannula, and an occluding member provided on the cannula that is movable between a collapsed orientation and an expanded orientation, the occluding member being sized and configured to occlude a patient""s aorta when in said expanded orientation. The occluding member comprises a non-inflatable structure which has an exterior that is impervious to fluid to substantially prevent fluid flow through a patient""s aorta when the occluding member is positioned in the aorta in the expanded orientation.
The non-inflatable structure preferably includes a plurality of individual support elements which move relative to each other as the occluding member moves between the collapsed and expanded orientations, an actuator being provided for moving the occluding member from one to the other of said collapsed and expanded orientations.
These and other aspects and advantages of the present invention will become apparent from the following description and drawings.